Long story short I bought a Ultrafine 5k off facebook marketplace for $450. It was in excellent cosmetic condition and never gave me any problems until this morning. It refuses to acknowledge a connection to my m1 macbook air. I tried unplugging and plugging in both the usb-c and power cable and get zero response from the monitor. It was working fine last night and this morning it won't turn on. My brother tells me our homes power flickered this morning if that could've caused anything. I also believe my laptop updated overnight to Ventura 13.2.1. Any help is much appreciated, LG is trying to charge me $150 to repair but don't even know the cause of the problem. Monitor was manufactured in November 2020 if that means anything.
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LG Ultrafine 5k randomly stops working
- Thread starter mchipset
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I had a 5k Ultrafine for about two years before it exhibited the same behavior, requiring me to constantly plug & unplug the thing to my laptop to get it to turn on. I had read about people having the same issue with no luck from LG repairing it (or it taking several weeks to do so). I ultimately gave up and just got a new display.
I was in the same boat as you, but I was told up front that it had issues where it would randomly turn off/on, or not connect at all. When this happens, sometimes my laptop would still pull a charge from the monitor, so I would know that it was technically working, just not getting a display signal.
Long story short, it turns out that the Thunderbolt connections on the main logic board in these monitors are very delicate and start losing contact over time. I ended up removing the main board and sending it to a repairman to re-solder the Thunderbolt connection and it fixed my issues. I will say, it hasn't been a perfect fix. It still acts up every now and then, and from what I've read, whether you get a new board or re-solder the one you have, it's basically a bandaid fix that could last for years or a couple months.
Long story short, it turns out that the Thunderbolt connections on the main logic board in these monitors are very delicate and start losing contact over time. I ended up removing the main board and sending it to a repairman to re-solder the Thunderbolt connection and it fixed my issues. I will say, it hasn't been a perfect fix. It still acts up every now and then, and from what I've read, whether you get a new board or re-solder the one you have, it's basically a bandaid fix that could last for years or a couple months.
There are so many issues with these monitors around the TB port. LG's board supplier used a very underrated connector and the tracks on the board just to thin for the currents pulled by a high power laptop. The whole area around the ports on the board overheats and the connector starts to delaminate pads and itself from the board, causing in many cases little actual damage, but the repair centre needs to use an uprated connector for a long term fix. Something like works very well: https://uk.farnell.com/gct-global-c...3-c/usb-conn-3-1-type-c-rcpt-24pos/dp/3648644
The only real solution is to have the ports replaced on the board and use a dock between the screen and the laptop so the display does not provide power to the laptop, this way these monitors will work for a very long time.
I would recommend the Dell WD22TB4 dock, this works great for me! Also Apples TB4 braided cables are a must as they offer a much tighter connection to the port on both sides compared to the LG cable.
The only real solution is to have the ports replaced on the board and use a dock between the screen and the laptop so the display does not provide power to the laptop, this way these monitors will work for a very long time.
I would recommend the Dell WD22TB4 dock, this works great for me! Also Apples TB4 braided cables are a must as they offer a much tighter connection to the port on both sides compared to the LG cable.
Hey mchipset, after you noticed your display was not working, did you try using a thunderbolt cable that you know to work fine/ok? More specifically, did you confirm that the display was failed and that it was not the cable itself? How do you know the display failed, not the cable? Were you using the factory supplied thunderbolt cable? And did you plug the cable in/out alot at the display end (not the end that goes into the macbook)?